I love dream sequences.
They tell you so much about the characters. They can reveal or hide the plot as needed. They can reveal things the characters should, but don't, know. They can be silly and funny or scary or romantic or almost any emotion you want. In terms of writing, I feel freest to do what I want in a dream sequence.
True, they often end up on the cutting room floor. But not always! And anything that helps you understand the characters is words and work well spent. So make your character take a nap and go for the wild, my friends. I want crazy dreams! Off the wall! Exciting! Adventurous! Go Inception-style if you want!
Dream on. Write on.